Method of preparing of progressiveburning smokeless powder and product thereof



UNITED STATES PATENT OFFICE METHOD OF PREPARING OF PROGRESSIVE- BURNING SMOKELESS POWDER AND PRODUCT THEREOF Floyd L. Boddicker, 'Ishpeming, Mich., assignor to Hercules Powder Company, Wilmington, DeL, a. corporation of Delaware No Drawing. Application October 13, 1936,

Serial No. 105,361

14 Claims. (01. 52-5) This invention relates to an improved method Now in accordance with my invention I may of preparation of progressive-burning smokeless utilize as a deterrent a water-soluble substance powder more particularly to an improved method and subject the powder grains and water solution of coating smokeless powder with a deterrent maof the deterrent to various temperatures for terial, and to smokeless powder coated with a various times, to effect a uniform coating of the 5 water-soluble deterrent material. powder grains with the deterrent. I may use As is well known, in order to render possible only suflicient of the aqueous solution of the declose control of the burning rate of smokeless terrent to moisten the grains, or I may use an powder and produce a high velocity of the proexcess of the aqueous deterrent solution and then jectile without high breech pressures, it has been remove such excess, in both cases finally drying customary to coat the grains of the smokeless the powder grains to remove the moisture therepowder with a deterrent material, explosive or from. non-explosive, which'will retard the burning rate In accordance with my invention I may utilize oi the powder grains. Such coating material deas water-soluble deterrents methyl cellosolve l5 sirably penetrates the powder grains more or adipate,thiodiglycol, thiodigylcol acetate, glycerol 1 less, so that as the powder burns, the successively diacetate. or other water-soluble smokeless powexposed surfaces contain gradually less and less der deterrent. Instead of glycerol diacetateImay of the deterrent material, thus causing the comuse die etin wh ch, as available commercially, bustlon of the grains to proceed with increasing may contain the monoand triacetates of glycerol speed, in varying amounts.

In order to efiect the coating of the powder As an example of the carrying out of the procgrains with the deterrent material and to obtain ess involving my invention. u g, for exthe desired degree of penetration of such map glycerol d tflte as the deterrent subterial, numerous processes have been devised, stance, two parts by e ht of a 15% nitroe. g., using dinitrotoluene as the deterrent maglycerin. fla powder Suitable for use in .22 calim terial, powder grains coated with dinitrotoluene be! rim fi e Ca tr dg s, was Wet with 0% by are subjected to heat, with or without the pres- Weight o Wate and p rts by weight of ence of moisture or water. By another method, g yce diflcetate added. e whole was then the powder grains are coated by treatment with P ace n a Sweetie b d run therein at a solution of dinitrotoluene in benzene, the ben- C. for 15 minutes, then at 55 C. for 15 mina zene evaporated, and penetration of the dinltroutes, the mass removed from the Sweetie barrel toluene obtained by immersing the coated powder and dried for hours at 55 C. grains in a hot water bath for several hours or As a further illustration of the carrying out several days. By still another method, using as of the process embodying my invention, one part 35 the deterrent material a mixture-of dimethylby weight of a 20% nitroglycerin rifle powder, &

diphenylurea and dinitrotoluene, or dimethylsuitable for use in large volume, center-fire rifle diphenylurea alone, the powder grains and detercartridges, was treated with a solution of 160 rent material are covered with water, and after p ts by We ght of a 5% S o of methyl mixing, heat is applied for varying periods. losolve adipate, first in the cold, then warmed 40 Treatment of smokeless powder grains to render up slowly to 90 C., maintained at 90 C. for 1 & their combustion progressive, by methods heretohour, removed from the Sweetie barrel and dried tore known, while productive of desired results for 3 days at 55 C. to a degree, has been open to a number of ob- Similarly, I may treat single base smokeless jections. For example, the use of a deterrent powders to render them progressive burning by and powder grains alone requires long-continued coating with a water-soluble deterrent.

heat and tumbling to obtain uniform distribution By virtue of my invention, not only are the of deterrent on the powder grains, and may lead powder grains uniformly coated and penetrated to explosions. The use of water with the deterby the water-soluble deterrent, but the desired rent and powder grains requires long treatment result is obtained without the attendant risk of and renders uniform coating diflicult on account overheating and explosion attending dry heating 60 of the water-insolubility of all deterrents hereof powder grains and deterrent, and without the tofore known. The use of a deterrent solvent. hazard of vapor poisoning and solvent recovery 9. g., benzol, is open to the great risk of explosion attending deterrent solution in volatile hydroof solvent vapors, their posionous nature, and carbons.

the economic necessity of recovery of the solvent. A further and highly advantageous result of? as my invention is that it enables the coating of double base smokeless powders with deterrent, without such injury to the powder as results from any attempt to coat such powders by processes involving water and water-insoluble deterrent alone, because the prolonged treatment of the powder grains by the hot water dissolves an appreciable quantity of nitroglycerin from the powder grains. By virtue of my invention, however, double base smokeless powder can be coated with deterrent, because the time of treatment and the quantity of water used are so small that no appreciable amount of nitroglycerin is removed, particularly when only sufllcient of the aqueous deterrent solution is used to moisten the grains of powder.

What I claim and desire to protect by Letters Patent is;

1. The method of coating smokeless powder grains with a deterrent which includes the step of surface coating of smokeless powder grains with a water-soluble deterrent substance.

2. The method'of coatingsmokeless powder with' a deterrent which includes treating smokeless powder with only sufficient of an aqueous solution of a deterrent substance to moisten the grains.

3. The method of coating smokeless powder grains with a deterrent which includes adding water to smokeless powder grains, adding a water-soluble deterrent to the mixture of smokeless powder grains and water, heating and agitating said mixture of smokeless powder, water and deterrent, and drying the coated smokeless powder grains.

4. Progressive burning smokeless powder com- 7 prising smokeless powder grains surface coated with a water-soluble deterrent material.

5. The method of coating smokeless powder grains with a deterrent which includes the step of surface coating of smokeless powder grains with a water-soluble, deterrent substance from the group consisting of diacetin, methyl cellosolve adipate, thiodiglycol, thiodiglycol diacetate and glycerol diacetate. V

6. The method of coating smokeless powder grains with a deterrent material which includes the step of surface coating smokeless powder grains with glycerol diacetate which is dissolved in an aqueous solution which is substantially free from other organic solvents.

'7. The method of coating smokeless powder grains with a deterent material which includes the step of surface coating smokeless powder grains with thiodiglycol which is dissolved in an aqueous solution which is substantially free from other organic solvents.

8. The method of coating smokeless powder grains with a deterrent material which includes the step of surface coating smokeless powder grains with methyl cellosolve adipate which is dissolved in an aqueous solution which is substantially free from other organic solvents.

9. Progressive burning smokeless powder com- .prising smokeless powder grains surface coated with a water-soluble deterent substance from the group consisting of diacetin, methyl cellosolve, adipate, thiodiglycol, thicdiglycol diacetate and glycerol diacetate.

10. Progressive burning smokeless powder comprising smokeless powder grains surface coated with glycerol diacetate.

11. Progressive burning smokeless powder comprising smokeless powder grains surface coated with thiodiglycol.

12. Progressive burning smokeless powder comprising smokeless powder grains surface coated with methyl cellosolve adipate.

13. The method of coating smokeless powder grains with a deterrent which includes treating smokeless powder grains with an excess of an aqueous solution of an organic deterrent substance, and removing said excess solution from the smokeess powder grains, said deterrent substance being dissolved in said aqueous solution which is substantially free from other organic solvents.

14. The method of coating smokeless powder grains with a deterrent which includes the step of surface coating smokeless powder grains with an organic deterrent substance which is dissolved in an aqueous solution which is substantially free from other organic solvents.

FLOYD L. BODDICKER. 

